How can tartar and plaque be removed from teeth without grinding? is there any paste, etc. for it?
The girders of a suspension bridge form an arc. The definition of an arc is a curve or bowed shape, like a part of a circle. An example of an arc is a rainbow. To arc is defined as to make a curved shape or move in a curved path.
The arc is convex toward the ocean and concave toward the continent with a deep trench running parallel to the arc along the convex (ocean) side. 1  Arcs and trenches are hundreds of miles long. 2  CROSS-SECTION. 3  Not all volcanic chains are island arcs, however, and not all island arcs are âislandsâ. For example, the Hawaiian Islands are an example of a linear chain of volcanoes in the middle of the Pacific Ocean that is not an island arc. Some âisland arcs have become parts of the continent; the Cascade Range of Washington and Oregon (remember Mt. St. Helens) and the Andes Mountains of South America are examples of âislandâ arcs that are part of continents.